Big End Horror

October 2005

When I started to drive her I found that the engine was very smooth, free from vibrations and quite. Much less mechanical noises then from my Desmo Quattro Monster. After about one year of driving I was thinking that maybe she start to make some unusual noises at idle. During normal driving it was normal but at idle, specially when she was missing a firing some times I was sure that I heard some new mechanical noise. I contacted some of the very nice knowledgeable  and helpful people at Bevelheads mail list for advise. They could just confirm what I was guessing. Conrod big end bearing is gone.  Front Cylinder went off and what do we find?

1.25mm axial play is to much. The expertise say that if it is more then 1mm it is all over. When I wiggle the small end FWD and back ot is about 2,5 mm movement. It is also possible to notice a very small radial play so it is for sure out of limit. Well this gives me a possibility to see how the engine looks on the inside and what condition it is. Except for the big end noise she runs like a dream and the gearbox is actually better then on a modern Ducati so I dont expect to find to much to worry about.

This cylinder and piston has more them 55000km. NiCaSil is a tough material. No signs of any troubles. The only thing that tells you it is not brand new is that it is a bit shiny

It looks like some one has already been here with the porting tools. As you can see she is also using a bit of oil so the heads will need a rebuild. After some telephone conversations with Guy Martin MBP there he talked me in to some upgrades I was thinking that she will have a bit of a porting job and bigger valves at the same time if money allows.

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